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Wednesday, July 24, 2013

It’s winter here in Western Australia and now that the mercury has started to drop to 1 degree Celsius overnight, we’re really starting to feel the cold. On the other side of the globe in the United States, they are suffering the opposite extremes, with temperatures in the high 30’ and low 40’s triggering terrifying bush fires in many areas.
Heat or the absence of it are a daily part of our lives and colour our conversations about the weather, fashion and lifestyle activities. But what is Heat and what happens when heat gets dangerous?
According to one dictionary definition, “Heat is the transfer of kinetic energy from one medium or object to another, or from an energy source to a medium or object. Such energy transfer can occur in three ways: radiation, conduction, and convection.”
We experience heat through radiation on a daily basis with the effect of infra-red radiation coming from the sun to heat our earth: on a more local level, we can experience the same effects from a domestic fireplace when the fire warms furniture within the room even though it may be some distance from the fire. Both these examples of heat through infrared radiation also demonstrate how these two forms of radiation can pose a potential danger to our health.
We expect to see the sun each day and forget that the sun, although a tremendous distance from our planet, is in fact a massive ball of gigantic thermonuclear reactions spewing out radiation in all directions - the miracle of it all is that our planet is in the so called Goldilocks position - just the right distance away not to be fried, and not too far away to be a snowball! It also has the advantage of having a magnetic field around it that protects us all from some of the sun’s more deadly radiation. But even though we are in such a blessed position, the infrared radiation from the sun still causes hundreds of thousands of preventible skin cancers around the world each year. And for some with the more deadly malignant melanoma, this can even threaten their lives. We must be more diligent in protecting ourselves and especially our little people by applying sunblock on a daily basis all year round, and wearing hats and sunglasses during the summer months. And if you love the great outdoors, you must remember to keep re-applying the sunblock as it can rub off those exposed areas.
On the domestic front, open fires are great for warming the home and for the older person, they are a wonderful place to just sit and reflect on some of life’s memories. But older folk are at risk of suffering radiation burns to their lower legs as sensation in those areas can diminish in people with Diabetes and other nerve damaging conditions. Also, open fires are a real danger to young children so please do protect them from open fires within the house, and barbecues and fire-pits outside the house.
Conduction is the next form of heat transfer and happens when two object are in direct contact and the warmer one will transfer heat to the cooler one until both are at the same temperature. A reviving example is coming in from the cold outdoors and soaking in a hot bath. But the interaction between something very hot and something colder can also have tragic effects on humans too. Just think of what happens when hot oils from a frypan get spilt on an inquisitive toddler in the kitchen: or if a youngster is just left for a short time in the bath and accidentally turns on the hot tap? - a dear friend of ours suffered such an injury and still has the scars from serious burns on his legs to show for it many years later - although he actually tells his kids that he got the scars from wrestling a crocodile! Another example of conduction of heat that can lead to short term pain is when you eat a mouthful of really hot food and burn the inside of your mouth. Always remember to check the temperature of food given to your little ones before they eat it - especially if its just come out of the microwave oven.
Convection is the final way that heat dissipates, and is the way that heat rises and then drops as it cools, in a room causing the air to circulate and finally warm the whole area. Heat from convection can be a problem if you lift the lid off a boiling saucepan, or open the door of a hot oven and have your face over the top of it, as the heat from steam can cause very nasty burns.
But heat isn’t the only form of energy that can lead to burns to we humans -
serious problems can occur as a result of electrical and chemical burns too. The first patient I ever attended as a medical student was a man who had been digging up the road in London with a pneumatic drill: disastrously, he hit a mains power line and suffered terrible flash burns to his body. I can still vividly recall his screams decades later as they changed his dressings on a daily basis! On the domestic front, electric irons and their dangling cords can be a great attraction to a crawling toddler and should be kept well away from them - in fact they should be designated a “no go zone” early on in every toddlers life! And remember to put plastic plugs in power outlets as little children can be tempted to poke things such as keys and sharp metal things into them with potentially terrible results.
Domestic chemicals such as oven cleaners and drain cleaners contain highly corrosive elements that can cause serious burns to the skin and should be kept far out of the reach of children. If contact does occur then :
Remove the cause of the burn by first rinsing the chemical off the skin surface with cool, gently running water for 10 to 20 minutes or more.
Remove clothing or jewelry that has been contaminated by the chemical.
Wrap the burned area loosely with a dry, dressing or a clean cloth.
Rewash the burned area for several more minutes if the person experiences increased burning after the initial washing.
and if in any doubt, or if there is continuing pain or blistering of the skin then seek prompt medical attention.
On a gloriously sunny day we should all be able to enjoy the privilege of living on the wonderful planet: but we should never take any of it for granted, but rather respect what we have - and that means taking measures that allow us, and our families, to enjoy our lifestyle and yet protect ourselves from any potential harm both within our homes and outdoors.

1 comment:

Very interesting reading - especially about all the different heat sources. Sometimes we forget the sun is a source of energy - we just want to see it because it warms us and makes our disposition sunny! It was good to review the different types of burns too.